That Frankenstein jawline and those skeletal cheekbones he debuted on the red carpet last night are all in the name of art, of course, as Gyllenhaal joins the club of weight-whittling (and waxing) actors. (Most recently indoctrinated member: Josh Brolin.)

In Nightcrawler, now filming in L.A., Gyllenhaal plays Lou, a freelance crime reporter who descends into the city's netherworld.

"It takes place in a land where I think there is a desert in a lot of ways: great opulence, and at the same time, great vastness and emptiness," the actor told Us Weekly at the Hollywood Film Awards.

"I knew that (Lou) was literally and figuratively hungry," so Gyllenhaal dove into a "mode where I was always a bit hungry."

Forget four-hour workouts and forsworn sweets: Gyllenhaal is maddeningly cryptic when it comes to just how he made the literal transformation and dropped around 20 pounds. "I just love this movie," he said. "That's how I did it. There really was no technique."